Panelboards, switchboards, and other electrical distribution devices are commonly used in residential, commercial, and industrial buildings. Individual circuit interrupters are mounted to these devices to protect branch circuits against overload and fault conditions. Basically, circuit interrupters like circuit breakers and fusible switches comprise a pair of separable contacts, a spring-operated mechanism for effecting separation of the contacts, and a tripping mechanism or fuse which automatically releases the operating mechanism upon the occurrence of an overload or fault condition.
Panelboards and the like are often constructed with bus bars or projecting lugs to form disconnect contacts for the removable individual circuit interrupters. These bus bars and lugs are rigidly attached to the upper surface of the panelboard support molding. Since the bus bars are exposed to the front of the panelboard, it is possible that an operator could be severely burned or shocked if they accidentally touched the terminals while installing the circuit breaker. Furthermore, the main circuit interrupter could be short circuited if conducting material accidentally bridged across the respective bus bars. The bus bars may also be subject to damage during the installation of other components near the panelboard.
Typically, the installation of a panelboard interior to a load center base requires special tools and a variety of different fasteners. The number of tools, parts and operations involved in the panelboard installation poses a high safety risk. Furthermore, many panelboard components are pre-set at the factory and are not readily adapted to various single and multi-phase installations.
In view of the increasing safety requirements for load centers and panelboards there is a need for an interior assembly which protects against accidental exposure to bus bars and is usable with components like circuit breakers already in the market. There is another need for an interior assembly which can be manually assembled in the field in a variety of combinations to fit various installations.